How to make a request grouped by date?

Question

Laravel

Comrades, fellow citizens, help me write a request correctly. The bottom line is this: there are operations with the creation date (created_at) and the amount (payment_sum). You need to make a request to withdraw the amount for all transactions by day.
In the database, the date is stored like this:
2019-10-23 10:41:41
In the controller, I have this:

$date = Carbon\Carbon::today()->subDays(7);

$todaySales = (Operation::query()
        ->select(DB::raw("created_at, SUM(payment_sum) as payment_sum"))
        ->where([
            ['user_id', Auth::id()],
            ['status', 100]])
        ->where('created_at','>',  $date)
        ->groupBy('columnForGroup')
        ->get());

        foreach ($todaySales as $todaySale){
            $date = $todaySale->created_at;
            $todaySale->date_at = $date->format('d/m');
        }

        return response()->json([
            'success' => true,
            'mass' => $todaySales,
        ]);

Answer 1

It is obvious to use a function in grouping
->groupBy("DATE_FORMAT(created_at, '%d-%m-%Y')")

Answer 2

Thanks for the answer. Decided already. If someone is interested, then did so.

->select(DB::raw("DATE(created_at) as day, count(payment_sum) as payment_sum"))